X0306 4 2021-12-10 0 0001657573 Xometry, Inc. XMTR 0001259278 CRONIN BILL C/O XOMETRY, INC. 7529 STANDISH PLACE SUITE 200 DERWOOD MD 20855 0 1 0 0 Chief Revenue Officer Class A Common Stock 2021-12-10 4 S 0 35369 45.8137 D 213660 D Class A Common Stock 2021-12-10 4 S 0 14501 46.269 D 199159 D Class A Common Stock 2021-12-10 4 S 0 130 47.25 D 199029 D The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $45.10 to $46.095, inclusive. The reporting person undertakes to provide to Xometry, Inc., any security holder of the Xometry, Inc. or the staff of the Securities and Exchange Commission, upon request,full information regarding the number of shares sold at each separate price within the ranges set forth in footnotes (1) and (2) to this Form 4. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $46.10 to $46.67, inclusive. /s/ Dorothy Vinsky, Attorney-in-Fact 2021-12-14